The invention is based on the patent application No. 2000-174338 Pat. filed in Japan, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an image forming apparatus, which can form images on a normal image display medium such as a normal paper sheet as well as a rewritable and reversible image display medium.
2. Description of the Background Art
At present, texts, graphics or the like prepared by a computer, a word processor or the like are displayed, for example, on a CRT display or the like, or are displayed by outputting them on a medium such as a paper sheet via a printer or the like.
However, the image display on the display such as a CRT display cannot achieve high resolutions as compared with images displayed, e.g., by printers on paper sheets, and can not display images with sufficiently high clearness and accuracy. Due to relatively low resolution and light emitted from the CRT or the like, an operation viewing images displayed on the CRT or the like for a long time causes fatigue in operator""s eyes.
In contrast to the above, the display of texts and graphics on the image display mediums such as paper sheets can be performed with high clearness and high resolution, and therefore can be easy-on-the-eyes image display.
For the above reasons, texts, graphics and others prepared by the computer, word processor or the like are output onto mediums such as paper sheets by a printer or the like in almost every case even when it is necessary to read only temporarily the text or the like, or the texts are a draft which may be further revised.
The mediums such as paper sheets bearing images are abandoned or burnt when they are no longer required. This results in consumption of a large mount of resources. The printer or the like also consumes a large amount of consumable products or materials such toner, ink or thermal transfer sheets. For obtaining the new display mediums such as paper sheets or the like as well as toner, ink or the like, manufacturing energies and resources are required.
This is contrary to the current demand for reduction in environmental loads.
Accordingly, an object of the invention is to provide an image forming apparatus which can form images on normal image display mediums such as normal paper sheets as well as reversible (i.e., image-writable, image-erasable and image-rewritable) image display mediums, can satisfy current demands for reduction in environmental loads relating to required resources, energies and others owing to image formation on the reversible image display mediums allowing rewriting and therefore repetitive use, and does not cause a substantial problem compared with the conventional image forming apparatus owing to conventional image formation on the normal image display mediums.
Also, an object of the invention is to provide an image forming apparatus which can prevent such a useless and erroneous operation that an image is formed on the image display medium of the type different from the type selected by an operator of the image forming apparatus.
Further, an object of the invention is to provide an image forming apparatus which can prevent such a useless and erroneous operation that the image formation for the reversible image display medium is effected on the reversible image display medium, which is arranged upside down.
Further, an object of the invention is to provide an image forming apparatus which can prevent such errors that the image formation for the reversible image display medium is effected on the normal image display medium, and that the image formation for the normal image display medium is effected on the reversible image display medium.
Further, an object of the invention is to provide an image forming apparatus, which can form images on either of the normal image display medium and the reversible image display medium, and further allows easy use.
The invention provides the following image forming apparatuses.
(1) First Image Forming Apparatus
An image forming apparatus including:
a first image forming portion for forming an image on a normal image display medium;
a second image forming portion for forming an image on a reversible image display medium; and
a medium type detecting device for detecting whether an image display medium to be subjected to the image formation is the normal image display medium or the reversible image display medium, wherein
the first or second image forming portion corresponding to the image display medium of the type detected by the medium type detecting device is allowed to perform the image formation when the medium type detecting device detects the image display medium of the same type as that selected by an operator, and the image formation on the image display medium of the type detected by the medium type detecting device is inhibited when the detected type is different from the selected type.
(2) An Image Forming Apparatus Including:
a first image forming portion for forming an image on a normal image display medium;
a second image forming portion for forming an image on a reversible image display medium; and
a medium type detecting device for detecting whether an image display medium to be subjected to the image formation is the normal image display medium or the reversible image display medium, wherein
the first or second image forming portion corresponding to the image display medium of the type detected by the medium type detecting device is allowed to perform the image formation when the medium type detecting device detects the image display medium of the same type as that selected by an operator, and the first or second image forming portion corresponding to the image display medium of the type different from that detected by the medium type detecting device is allowed to perform the image formation when the detected type is different from the selected type.
(3) An Image Forming Apparatus Including:
a first image forming portion for forming an image on a normal image display medium;
a second image forming portion for forming an image on a reversible image display medium; and
a medium type detecting device for detecting whether an image display medium to be subjected to the image formation is the normal image display medium or the reversible image display medium, wherein
the first or second image forming portion corresponding to the image display medium of the type detected by the medium type detecting device is allowed to perform the image formation when the medium type detecting device detects the image display medium of the same type as that selected by an operator, and the image display medium of the type detected by the medium type detecting device is discharged without image formation when the detected type is different from the selected type.
(4) An Image Forming Apparatus Including:
a first image forming portion for forming an image on a normal image display medium;
a second image forming portion for forming an image on a reversible image display medium;
a medium type detecting device for detecting whether an image display medium to be subjected to the image formation is the normal image display medium or the reversible image display medium; and
a medium surface direction detecting device for detecting whether the front and rear surfaces of the reversible image display medium are faced in predetermined directions, respectively, wherein
the image formation by the second image forming portion is allowed when the image display medium detected by the medium type detecting device is the reversible image display medium and the medium surface direction detecting device detects the predetermined directions of the front and rear surfaces of the reversible image display medium, and the image formation by the second image forming portion is inhibited when the front and rear surfaces of the reversible image display medium are not faced in the predetermined directions.
(5) An Image Forming Apparatus Including:
a first image forming portion for forming an image on a normal image display medium;
a second image forming portion for forming an image on a reversible image display medium;
a medium type detecting device for detecting whether an image display medium to be subjected to the image formation is the normal image display medium or the reversible image display medium; and
a medium surface direction detecting device for detecting whether the front and rear surfaces of the reversible image display medium are faced in predetermined directions, respectively, wherein
the image formation by the second image forming portion is allowed when the image display medium detected by the medium type detecting device is the reversible image display medium and the medium surface direction detecting device detects the predetermined directions of the front and rear surfaces of the reversible image display medium, and the reversible image display medium is discharged without image formation when the front and rear surfaces of the reversible image display medium are not faced in the predetermined directions.
The fourth and fifth image forming apparatuses may be configured such that the image formation by the first image forming portion is allowed independently of the directions of the front and rear surfaces of the medium, if the medium type detecting device detects the normal image display medium.
The normal image display medium is a normal paper sheet, a sheet for overhead projector or the like.
The reversible image display medium is a rewritable (i.e., image-writable, image-erasable and image-rewritable) medium such as a reversible image display medium of an electric field drive type or a magnetic drive type. The reversible image display medium will be described later.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.